1. Field of the Invention
The present invention is generally related to a method for controlling the operation of an internal combustion engine and, more particularly, to a method for selecting appropriate operational relationships between various parameters of the engine of an outboard motor based on the specific and particular intended application of the outboard motor.
2. Description of the Prior Art
Internal combustion engines can be tuned, or calibrated, to operate in specific ways under a particular set of conditions. Those skilled in the art of internal combustion engines, and particularly in the field of outboard motors, are aware of various changes that can be made in the relationship between engine operating parameters which can result in desired operating characteristics.
U.S. Pat. No. 6,405,714, which issued to Bylsma et al on Jun. 18, 2002, described a method and apparatus for calibrating and controlling fuel injection. A method for calibrating an electronic control unit for an internal combustion engine is described. The electronic control unit may have multiple channels with each channel being adapted to provide an input drive signal to a fuel delivery apparatus. A first channel is selected for calibration. A reference signal of desired and known parameters is also defined. The reference signal is defined such that it is indicative of the cyclical performance of a fuel delivery apparatus such as a fuel injection device. A command signal is generated and passed through the circuitry of the selected channel. The channel circuitry generates a drive signal in response to the command signal. A desired parameter of the drive signal is measured for comparison with the known parameter of the reference signal. If necessary, the command signal is then adjusted so as to produce a modified drive signal which has a parameter with reduced variation from the known reference parameter.
U.S. Pat. No. 5,426,585, which issued to Stepper et al on Jun. 20, 1995, describes a method and apparatus for generating calibration information for an electronic engine control module. A method and apparatus for generating calibration information in which a subfile type is defined for each of a plurality of categories of data including engine control data, engine family data, vehicle interface data, software sequencing data, electronic configuration data, and memory configuration data is described. A separate subfile is created in memory for each of the plurality of individual sets of data in each of the data categories. Each subfile is automatically provided with line checksums, a cyclic redundancy code, date information, a subfile type identifier, and a subfile authorization level, and data entries are automatically verified based on rules stored in memory in a rules file, each of the subfile types having an associated rules file, and each of the rules files defining criteria for individual data items and for interrelationships between data items in its associated subfile type. A compatibility file is created in memory to identify subfile of one type which are compatible with a subfile of another type. Each subfile and the compatibility file are distributed individually via an electronic communication link to multiple service computers programmed to determine compatibility among selected subfiles based on information stored in the compatibility file and to assemble compatibility subfiles into a calibration file for a particular engine control module.
U.S. Pat. No. 4,438,497, which issued to Willis et al on Mar. 20, 1984, describes an adaptive strategy to control an internal combustion engine. The specification discloses a method for adaptively controlling engine calibration control values. The strategy includes the steps of predicting a driving pattern based on analysis of recent past driving patterns and selecting engine control values appropriate for the predicted driving pattern and a desired emission constraint. The adaptive strategy adjusts spark timing and magnitude of EGR as a function of engine energy usage per distance traveled while maintaining feedgas emissions at a constant level over a wide variety of driving patterns including urban, suburban and highway. A plurality of driving cycle segments are analyzed to generate a table of engine calibration control values for the adaptive spark and EGR control strategy. This adaptive strategy has fuel consumption characteristics which are most advantageous at the most constrained feedgas levels. Drivability can be enhanced because of the greater calibration flexibility inherent in the adaptive technique.
U.S. Pat. No. 6,439,188, which issued to Davis on Aug. 27, 2002, discloses a four cycle four cylinder in-line engine with rotors of a supercharging device used as balance shafts. A four cycle four cylinder in-line internal combustion engine is provided with a housing structure that contains two shafts which rotate in opposite directions to each other and at the same rotational velocity. Pairs of counterweights are attached to the two shafts in order to provide a counterbalance force which is generally equal to and opposite from the secondary shaking force which results from the reciprocal movement of the pistons of the engine. The first and second shafts are rotors of a supercharging device, such as a Roots blower. The rotational speed of the first and second shafts is twice that of the rotational speed of the crankshaft of the engine and the provision of counterweights on the first and second shafts balances the secondary forces caused by the reciprocal motion of the pistons in the engine.
U.S. Pat. No. 6,408,832, which issued to Christiansen on Jun. 25, 2002, discloses an outboard motor with a charge air cooler. The outboard motor is provided with an engine having a screw compressor which provides a pressurized charge for the combustion chambers of the engine. The screw compressor has first and second screw rotors arranged to rotate about vertical axes which are parallel to the axis of a crankshaft of the engine. A bypass valve regulates the flow of air through a bypass conduit extending from an outlet passage of the screw compressor to the inlet passage of the screw compressor. A charge air cooler is used in a preferred embodiment and the bypass conduit then extends between the cold side plenum of the charge air cooler and the inlet of the compressor. The charge air cooler improves the operating efficiency of the engine and avoids overheating the air as it passes through the supercharger after flowing through the bypass conduit. The bypass valve is controlled by an engine control module in order to improve power output from the engine at low engine speeds while avoiding any violation of existing limits on the power of the engine at higher engine speeds.
U.S. Pat. No. 6,405,692, which issued to Christiansen on Jun. 18, 2002, discloses an outboard motor with a screw compressor supercharger. The outboard motor is provided with an engine having a screw compressor which provides a pressurized charge for the combustion chambers of the engine. The screw compressor has first and second screw rotors arranged to rotate about vertical axes which are parallel to the axis of a crankshaft of the engine. A bypass valve regulates the flow of air through a bypass conduit extending from an outlet passage of the screw compressor to the inlet passage of the screw compressor. A charge air cooler is used in a preferred embodiment and the bypass conduit then extends between the cold side plenum of the charge air cooler and in the inlet of the compressor. The bypass valve is controlled by an engine control module in order to improve power output from the engine at low engine speeds while avoiding any violation of existing limits on the power and the engine at higher engine speeds.
U.S. Pat. No. 6,378,506, which issued to Suhre et al on Apr. 30, 2002, discloses a control system for an engine supercharging system. A bypass control valve is controlled by an engine control module as a function of manifold absolute pressure and temperature within an air intake manifold in conjunction with the barometric pressure. An air per cylinder (APC) magnitude is calculated dynamically and compared to a desired APC value which is selected as a function of engine operating parameters. The air per cylinder value is calculated as a function of the manifold absolute pressure, the cylinder swept volume, the volumetric efficiency, the ideal gas constant, and the air inlet temperature. The volumetric efficiency is selected from stored data as a function of engine speed and a ratio of manifold absolute pressure to barometric pressure.
U.S. Pat. No. 5,848,582, which issued to Ehlers et al on Dec. 15, 1998, describes an internal combustion engine with barometric pressure related start of air compensation for a fuel injector. The control system is provided with a method by which the magnitude of the start of air point for the injector system is modified according to the barometric pressure measured in a region surrounding the engine. This offset, or modification, of the start of air point adjusts the timing of the fuel injector system to suit different altitudes at which the engine may be operating.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
When calibrating an internal combustion engine, the goal is usually to develop a calibration scheme which satisfies a wide variety of running conditions that the engine can experience. For example, the engines of outboard motors can be used for waterskiing, fishing, high-performance, or commercial markets. Each of these uses and applications of outboard motor engines can operate more efficiently if different engine characteristics could be provided in the calibration procedure. However, since the specific use and application of the engine of an outboard motor is often unknown and cannot always be predicted accurately, a typical calibration procedure applies certain accommodations that are made in order to calibrate the engine in an acceptable manner for any and all of the potential uses. These accommodations may affect torque, acceleration, fuel economy, idle operation quality, knock, and other operating characteristics. The result of this technique is to create a calibration which achieves average performance in all of these categories.
In certain marine applications, a manually controlled throttle handle is used to electronically control the throttle of an engine of a marine propulsion system. In other words, no cables or mechanical linkages are employed between the manually controlled throttle handle and the throttle body of the engine. In applications like this, it could be beneficial if the relationship of movement between the throttle handle and the throttle plate within the throttle body could be made changeable according to the specific application of the engine. For example, in a racing application one response profile might be most desirable, whereas in a trolling operation a different profile is most desirable.
It would therefore be significantly beneficial if a method could be provided to quickly and efficiently change the operation of the engine from one calibration scheme to another at the request of the operator of the marine vessel.
A method for controlling the operation of an internal combustion engine, made in accordance with the preferred embodiment of the present invention, comprises the steps of providing a first set of operational relationships which is preselected for use in a first type of application of the internal combustion engine. It also comprises the step of providing a second set of operational relationships which is preselected for use in a second type of application of the internal combustion engine. The method further comprises the step of monitoring a manually selectable parameter and selecting a chosen set of operational relationships from the first and second sets, as a function of the selectable parameter. It also comprises the step of controlling the operation of the internal combustion engine according to the chosen set of operational relationships. The manually selectable parameter can be a resistance magnitude of a resistance component, a manual selection made through the use of a data entry terminal, or a status of one or more switches.
The first and second sets of operational relationships can comprise a plurality of values of engine operating speeds, each of which is stored as a function of a position of a manually movable throttle selector. Alternatively, the first and second sets of operational relationships can comprise a plurality of ignition timing values stored as a function of engine speed and load value, a plurality of values of a duration of air injection through a fuel injector stored as a function of engine operating speed and load value, a plurality of values of an amount of fuel injected through a fuel injector during each injector event stored as a function of engine speed and load value, a plurality of fuel injection timing values stored as a function of engine speed and load value, or a plurality of throttle plate positions for a supercharger bypass conduit stored as a function of engine speed.